Preamble with detectable wlan version identification

ABSTRACT

Systems and methods for generating a control signal for automatic wireless network version detection of a transmission. The control signal enables a receiver to detect the wireless network version detection of the transmission, so that the proper wireless network version is used for interpreting signaling information and decoding of the payload of the transmission. In some examples, the control signal is within a preamble of the transmission. The wireless network version can be an IEEE 802.11 version, such as proposed IEEE 802.11be. The control signal is compatible with legacy systems and can indicate the legacy signaling information by way of a Legacy Signal (SIG) (L-SIG) symbol. In some examples, the control signal can indicate the wireless network version by using an identifier symbol which is generated from at least part of, but is not identical to, the L-SIG symbol.

CROSS REFERENCE

This application is a continuation of U.S. patent application Ser. No.17/862,279 filed Jul. 11, 2022, which is a continuation of U.S. patentapplication Ser. No. 16/944,993 filed Jul. 31, 2020 which issued as U.S.Pat. No. 11,387,937 on Jul. 12, 2022, which claims the benefit ofpriority to U.S. Provisional Patent Application No. 62/884,136 filedAug. 7, 2019, all the entire contents of which are herein incorporatedby reference into the Detailed Description herein below.

TECHNICAL FIELD

Example embodiments relate to wireless communications, in particularsystems and methods for detecting a wireless local area network (WLAN)version of a transmission.

BACKGROUND

The Institute of Electrical and Electronics Engineers (IEEE) setsstandards for wireless communication technologies, including wirelesslocal area network (WLAN) communication technologies. The IEEE 802.11family of standards relate to WLANs and their quality of service (QoS),access point protocol, security enhancement, wireless management, etc.

There are different wireless network versions of IEEE 802.11. Theversions include 802.11a, 802.11g (Extended Rate Physical Layer (PHY),ERP), 802.11n (High Throughput, HT), 802.11ac (Very High Throughput,VHT), and 802.11ax (High Efficiency, HE). There are increasing demandson traffic caused by video streaming, cloud computing,Internet-Of-Things (IOT), big data, Augmented Reality/Virtual Reality(AR/VR), and other factors. New versions of WLAN are being developed tomeet the requirements for high transmission data rates. For example, arecent Task Group called “TGbe” in IEEE 802.11 was formed to develop anext generation 802.11 WLAN standard, called IEEE 802.11be (also knownas Extremely High Throughput, EHT). IEEE 802.11be has a target ofmaximum throughput of 30 Gigabits per second (Gbps) with carrierfrequency operation between 1 and 7.250 GigaHertz (GHz) while ensuringbackward compatibility and coexistence with legacy IEEE 802.11 compliantdevices operating in the 2.4 GHz, 5 GHz, and 6 GHz bands.

A wireless communication device is required to know which version ofIEEE 802.11 is being used in a communication frame so as to properlyinterpret or respond to the communication frame. The device can alsobenefit from knowing what type of frame is being communicated. As well,the frame needs to be compatible with legacy versions along with currentversions of IEEE 802.11.

Accordingly, it would be desirable to provide a solution for efficient,backward-compatible, low-error and robust detection of the particularWLAN version of a communication. It would also be desirable to provide acommunication format that indicates the type of frame beingcommunicated.

SUMMARY

Example embodiments relate to a control signal that enables automaticdetection of a wireless network version (PHY type) of a transmission, sothat the wireless network version can be used for interpreting signalinginformation and decoding of the payload of the transmission. In someexample embodiments, the control signal is within a preamble of thetransmission. The wireless network version can be an IEEE 802.11version, such as proposed IEEE 802.11be. The control signal iscompatible with legacy systems and can indicate the legacy signalinginformation by way of a Legacy Signal (SIG) (L-SIG) field.

The receiver can be configured to automatically detect the specificwireless network version of the transmission, which can be a PhysicalLayer Convergence Procedure (PLCP) Protocol Data Unit (PPDU). Thereceiver can then correctly conduct further interpretation of signalinginformation and payload data carried by the PPDU. It is desirable thatautomatic wireless network version detection be performed at an earlystage in the PPDU detection, e.g. after detection of the PPDU packet andperformance of frequency channel estimation. The particular wirelessnetwork version can then be applied in order to further interpret thesignaling information, decode the received payload data, and performother functions. Example embodiments of PPDU with auto-detection can beapplied to the proposed IEEE 802.11be (EHT) as well as other wirelesscommunication versions.

In some wireless communication versions, the indication of data rate inL-SIG is fixed. For example, in IEEE 802.11ax and the proposed IEEE802.11be the data rate is indicated to be fixed at 6 Megabits per second(Mb/s) in L-SIG. Some example embodiments do not require repeating ofrate information because the pre-defined data rate is described in acorresponding SIG field once that particular wireless network version isidentified, and therefore the rate is known to the receiver.

An example embodiment is a method for enabling wireless network versiondetection, performed by a wireless communication device, the methodincluding: generating a control signal for a transmission, the controlsignal including i) a Legacy Signal (SIG) (L-SIG) symbol and ii) anidentifier symbol which is generated from at least part of, but is notidentical to, the L-SIG symbol, the identifier symbol indicating awireless network version of the transmission; and transmitting thecontrol signal.

In another example embodiment of the method, a L-SIG field of the L-SIGsymbol includes a Rate subfield and a Length subfield, and wherein anidentifier field of the identifier symbol includes a Cyclic RedundancyCheck (CRC) subfield in the same corresponding bit positions as the Ratesubfield of the L-SIG field, wherein the CRC subfield protects the Ratesubfield and the Length subfield, wherein the CRC subfield indicates thewireless network version of the transmission.

In another example embodiment of the method, the method furtherincludes, prior to said transmitting, encoding the CRC subfield withblock convolutional code (BCC) encoding.

In another example embodiment of the method, the BCC encoding is coderate one half BCC encoding.

In another example embodiment of the method, the identifier fieldfurther includes a Tail subfield, the method further including, prior tosaid transmitting, encoding the CRC subfield and the Tail subfield withblock convolutional code (BCC) encoding.

In another example embodiment of the method, the identifier fieldincludes, prior to said transmitting, encoding the CRC subfield withtail-biting block convolutional code (BCC) encoding.

In another example embodiment of the method, the identifier fieldincludes the Cyclic Redundancy Check (CRC) subfield repeated at leastonce in same corresponding bit positions as a Tail subfield of the L-SIGfield.

In another example embodiment of the method, an identifier field of theidentifier symbol includes a Flag subfield in same corresponding bitpositions as a Rate subfield of a L-SIG field of the L-SIG symbol,wherein the Flag subfield indicates the wireless network version of thetransmission.

In another example embodiment of the method, the identifier fieldincludes the Flag subfield repeated at least once in same correspondingbit positions as a Tail subfield of the L-SIG

FIELD

In another example embodiment of the method, an identifier field of theidentifier symbol is generated by interleaving or scrambling an L-SIGfield of the L-SIG symbol with a specified interleaver or a specifiedscrambling sequence, wherein the interleaved or scrambled L-SIG fieldindicates the wireless network version of the transmission.

In another example embodiment of the method, the method furtherincludes, prior to said transmitting, performing Inverse Fast FourierTransform on the control signal over one or more sub-carriers to timedomain, wherein the identifier symbol is a cyclic shifted version, inthe time domain, of the L-SIG symbol.

In another example embodiment of the method, the transmitting includestransmitting the identifier symbol after the L-SIG symbol.

In another example embodiment of the method, the indicated wirelessnetwork version is an Institute of Electrical and Electronics Engineers(IEEE) 802.11 version or an amendment version of the IEEE 802.11version.

Another example embodiment is a method for enabling wireless networkversion detection, performed by a wireless communication device, themethod including: generating a control signal for a transmission, thecontrol signal including: a Legacy Signal (SIG) (L-SIG) field, aRepeated L-SIG (RL-SIG) field, and an identifier separate from the L-SIGfield and the RL-SIG field, the identifier indicating i) a wirelessnetwork version of the transmission and ii) a frame type of thetransmission; and transmitting the control signal.

In another example embodiment of the method, the indicated wirelessnetwork version includes an indication of an amendment version of theindicated wireless network version.

In another example embodiment of the method, the indicated wirelessnetwork version is an Institute of Electrical and Electronics Engineers(IEEE) 802.11 version or an amendment version of the IEEE 802.11version.

In another example embodiment of the method, the indicated frame type isa multi-user (MU) frame type, a single user (SU) frame type, a triggerbased (TB) frame type, or an extended range (ER) TB frame type.

In another example embodiment of the method, the identifier is within asignal (SIG) field particular to signaling information of the indicatedwireless network version.

In another example embodiment of the method, the control signal is aseparate field from a signal (SIG) field particular to signalinginformation of the indicated wireless network version.

In another example embodiment of the method, the transmission is anuplink transmission, wherein the control signal is within a triggerframe for soliciting the uplink transmission, wherein the identifier isan identifier field or identifier subfield of the trigger frame.

In another example embodiment of the method, bits of the identifierincludes shared bits that indicate both i) the wireless network versionof the transmission and ii) the frame type of the transmission.

In another example embodiment of the method, the identifier issubsequent to the L-SIG field and the RL-SIG field within the controlsignal.

In another example embodiment of the method, the method furtherincludes, prior to the transmitting, modulating the identifier as oneorthogonal frequency-division multiplexing symbol.

In another example embodiment of the method, the transmitting includestransmitting the identifier field after the L-SIG field and the RL-SIGfield.

Another example embodiment is a method for detecting a wireless networkversion of a transmission, performed by a wireless communication device,the method including: receiving a control signal for a transmission, thecontrol signal including i) a Legacy Signal (SIG) (L-SIG) symbol and ii)an identifier symbol which is generated from at least part of, but isnot identical to, the L-SIG symbol, the identifier symbol indicating awireless network version of the transmission; and interpreting thecontrol signal in accordance with the indicated wireless networkversion.

Another example embodiment is a method for detecting a wireless networkversion of a transmission, performed by a wireless communication device,the method including: receiving a control signal for a transmission, thecontrol signal including a Legacy Signal (SIG) (L-SIG) field, a RepeatedL-SIG (RL-SIG) field, and an identifier separate from the L-SIG fieldand the RL-SIG field, the identifier indicating i) a wireless networkversion of the transmission and ii) a frame type of the transmission;and interpreting the control signal in accordance with the indicatedwireless network version.

An example embodiment is a wireless communication device, comprising anantenna; a processing device; and a memory associated with theprocessing device for storing instructions that when executed by theprocessing device causes the processing device to perform any of thedescribed methods, processes or functions.

An example embodiment is a non-transitory computer-readable medium whichstores instructions that when executed by a processing device causes theprocessing device to perform any of the described methods, processes orfunctions.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present example embodiments,and the advantages thereof, reference is now made to the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1A is a schematic diagram illustrating a wireless communicationsystem for multiple access communications according to an exampleembodiment;

FIG. 1B is a schematic diagram of uplink (UL) and downlink (DL)transmissions of the wireless communication system according to anexample embodiment;

FIG. 1C is a schematic representation of an example wirelesscommunication device according to an example embodiment;

FIG. 2 illustrates a graph of resource units for multiple accesscommunications of the wireless communication system, according to anexample embodiments;

FIG. 3A is a schematic diagram of a transmitter according to an exampleembodiment;

FIG. 3B is a schematic diagram of a receiver according to an exampleembodiment;

FIG. 4A illustrates an Orthogonal Frequency-Division Multiplexing (OFDM)Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU)according to IEEE 802.11a or IEEE 802.11g (generically “802.11a/g”);

FIG. 4B illustrates a signal (SIG) field of the OFDM PPDU of FIG. 4Aaccording to IEEE 802.11a/g;

FIG. 4C illustrates an example method of encoding and modulation the SIGfield of FIG. 4B according to IEEE 802.11a/g;

FIG. 5 illustrates an OFDM High Efficiency (HE) PPDU according to IEEE802.11ax;

FIG. 6 illustrates an example of an OFDM PPDU having auto-detectablewireless network version indication using a Partial Repeated LegacySignal (SIG) (PRL-SIG) field, in accordance with an example embodiment;

FIG. 7 illustrates an example embodiment of the PRL-SIG field shown inFIG. 6 , including a Cyclic Redundancy Check (CRC) subfield;

FIG. 8 illustrates an example method of encoding the PRL-SIG field ofFIG. 7 ;

FIG. 9 illustrates an example method of detecting the PRL-SIG field fromthe signal generated by the method of FIG. 8 ;

FIG. 10 illustrates another example method of encoding the PRL-SIG fieldof FIG. 7 ;

FIG. 11 illustrates an example method of detecting the PRL-SIG fieldfrom the signal generated by the method of FIG. 10 ;

FIG. 12 illustrates a second example embodiment of the PRL-SIG fieldshown in FIG. 6 , which includes the Cyclic Redundancy Check (CRC);

FIG. 13 illustrates an example method of encoding the PRL-SIG field ofFIG. 12 ;

FIG. 14 illustrates an example method of detecting the PRL-SIG fieldfrom the signal generated by the method of FIG. 13 ;

FIG. 15 illustrates an example embodiment of the PRL-SIG field shown inFIG. 6 , having a Flag subfield;

FIG. 16 illustrates another example embodiment of the PRL-SIG fieldshown in FIG. 6 having a Flag subfield;

FIG. 17A illustrates a first example embodiment of an OFDM PPDU forindicating both the Physical Layer (PHY) version and the frame-type ofthe OFDM PPDU;

FIG. 17B illustrates a second example embodiment of an OFDM PPDU forindicating both PHY version and frame-type;

FIG. 17C illustrates a third example embodiment of an OFDM PPDU forindicating both PHY version and frame-type;

FIG. 17D illustrates a fourth example embodiment of an OFDM PPDU forindicating both PHY version and frame-type;

FIG. 17E illustrates an example indicator for indicating both PHYversion and frame-type, in accordance with an example embodiment;

FIG. 18A illustrates an example embodiment of an OFDM PPDU havingauto-detectable wireless network version indication using an InterleavedRL-SIG (IRL-SIG) field;

FIG. 18B illustrates an example embodiment of an OFDM PPDU havingauto-detectable wireless network version indication using a ScrambledRL-SIG (SRL-SIG) field;

FIG. 19 illustrates an example method of encoding the IRL-SIG field ofthe PPDU of FIG. 18A; and

FIG. 20 illustrates an example method of detecting the IRL-SIG fieldfrom the signal generated by the method of FIG. 19 ;

FIG. 21 illustrates an example of an OFDM PPDU having auto-detectablewireless network version indication using a Cyclic Shifted RL-SIG(CS-RL-SIG) field, in accordance with an example embodiment;

FIG. 22 illustrates an example method of encoding the CS-RL-SIG field ofFIG. 21 ;

FIG. 23 illustrates an example method for enabling automatic wirelessnetwork version detection within transmissions, in accordance with anexample embodiment.

Similar reference numerals may have been used in different figures todenote similar components.

DETAILED DESCRIPTION

Example embodiments relate to a control signal that enables automaticwireless network version detection of a transmission, so that thewireless network version can be used for interpreting the control signaland the transmission. In some example embodiments, the control signal iswithin a preamble of the transmission. The wireless network version canbe an IEEE 802.11 version, such as proposed IEEE 802.11be. The controlsignal is compatible with legacy systems and can indicate the legacysignaling information by way of a Legacy Signal (SIG) (L-SIG) field.

FIG. 1A provides an example schematic diagram of a wirelesscommunication system 100 in which example embodiments may beimplemented. The wireless communication system 100 includes an accesspoint (AP, also known as an AP STA or a network coordinator) 101 and atleast one station (STA, also known as non-AP STA) 102 in a wirelesscommunication network, such as a wireless local area network (WLAN). TheAP 101 is any entity that has STA functionality and provides access tothe Internet or a distribution service for the associated STAs 102. TheSTAs 102 may be mobile communication devices enabled for wirelesscommunications, including but not limited to mobile phones, smartphones, laptops, tablet computers, machine-type communication devices,Internet of Things (IoT) devices, and wireless sensing and reportingdevices. The AP 101 and the STAs 102 can each be configured to executeuplink (UL) and downlink (DL) transmissions in the WLAN.

In the WLAN, the AP 101 may provide access to the Internet or adistribution service for one or more STAs 102 that are wirelessly andcommunicatively associated with the AP 101. The AP 101 can access theInternet or the distribution service by way of wired or wirelesscommunication. Although only one single AP 101 is shown, this is onlyillustrative and is not intended to be limiting. In other examples,there may be more than one AP 101 within the wireless communicationsystem 100.

Referring to FIG. 1B, examples of the WLAN will be described in thecontext of wireless communications between a plurality of STAs 102 andan AP 101. The wireless communication system 100 supports multi-usermultiple input multiple output (MU-MIMO) transmissions, also known as amultiple access transmissions. The AP 101 and at least one of the STAs102 may be configured for single user (SU) communications in otherexamples (not shown here). MU-MIMO based transmission, which can usemultiple antennas, allows simultaneous channel access by the STAs 102for effective use of frequency channels in the WLAN. The AP 101 cansimultaneously transmit spatial-multiplexed data to the STAs 102.Payload data can be simultaneously transmitted by the AP 101 to the STAs102 using a plurality of respective spatial streams (stream 1, 2, 3shown in FIG. 1B) in the DL direction, shown as DL MU transmissions120(1) to 120(3) (generically referred to as DL MU transmission 120). Inthe DL direction, payload data transmitted to each STA 102 may bedifferent for each STA 102. In the UL direction, payload data can besimultaneously transmitted to the AP 101 using a plurality of respectivespatial streams (stream 4, 5, 6 shown in FIG. 1B), shown as UL MUtransmissions 121(1) to 121(3) (generically referred to as UL MUtransmission 121). The DL MU transmissions 120 and the UL MUtransmissions 121 are payload transmissions. The DL MU transmissions 120and the UL MU transmissions 121 may use Orthogonal Frequency DivisionMultiple Access (OFDMA), with MU-MIMO or without MU-MIMO.

Reference is now made to FIG. 2 , which illustrates an OFDMAtransmission scheme to multiplex communications with a plurality of STAs102 over different frequencies (f) and times (t). The OFDMA is amultiple access scheme where different subsets of sub-carriers areallocated to different STAs 102, allowing the AP 101 to have datacommunication with the different STAs 102 (e.g., STAs 102(1) to 102(4)as shown in FIG. 2 ). The STAs 102 can have data transmission scheduledacross both frequency (such as sub-carriers 200(1) to 200(n)(generically referred to as sub-carrier 200) and time. As shown in FIG.2 , transmission frequency channels are divided into smallersub-channels with a predefined number of sub-carriers. A Resource Unit(RU) 201 includes a plurality of sub-carriers, typically with a minimumsize of 26 sub-carriers 200. The RU 201 has a maximum number ofsub-carriers that can be used by one or more of the STAs 102. The AP 101can assign each STA 102 one or more RUs in order to perform a UL or DLtransmission, or can assign multiple STAs 102 to a RU.

Reference is now made to FIGS. 3A and 3B, wherein FIG. 3A illustrates atransmitter 310 and FIG. 3B illustrates a receiver 320, in accordancewith example embodiments. In example embodiments, the transmitter 310 isconfigured to encode the preamble and payload data of the PPDU, and thentransmit the PPDU. The receiver 320 is configured to receive the PPDU,as applicable. In some examples, the receiver 320 first decodes part ofthe preamble of the received UL or DL PPDU in order to determine awireless network version of the PPDU, and then the receiver 320 isconfigured to interpret the preamble and the payload according to thedetermined wireless network version. In some examples, the transmitter310 and the receiver 320 are used to communicate trigger frames in orderto solicit the UL PPDU.

The transmitter 310 is configured to transmit PPDU. In some examples,the transmitter 310 may be included within the AP 101 or the STA 102 toimplement the DL or UL transmission, respectively. For example, in DLdirection, the transmitter 310 may be included within the AP 101 totransmit PPDU containing a preamble and respective payload data to STAs102 on their respective sub-carriers in one or more RUs. In ULdirection, the transmitter 310 may be included within an associated STA102 to transmit preamble and payload data of the STA 102 on itsrespective sub-carriers in one or more RUs.

As shown in FIG. 3A, the transmitter 310 includes a plurality oftransmitting (Tx) paths 311(1) to 311(Z) (generically referred to as Txpath 311) for a transmission that includes a preamble and payload data.When the transmitter 310 is in the AP 101, for DL transmission, the AP101 can generate Tx paths 311 for different respective STAs (e.g., STA 1to STA Z).

One Tx path 311 for one STA 102 will now be described in detail. Aseries of bits are received by the symbol modulator 312 in the Tx path311. The symbol modulator 312 performs symbol modulation on the bits ofthe payload data to data symbols (also known as a constellationsymbols). The data symbols can be represented as amplitude and phase, orcosine and sine coefficients, or other nomenclatures, as is understoodin the art. Each data symbol may be referred to as a chip. The symbolmodulation can be based on symbol modulation schemes such asamplitude-shift keying (ASK), phase-shift keying (PSK), binary PSK(BPSK), quadrature PSK (QPSK), quadrature amplitude modulation (QAM), orany other appropriate method of mapping series of data bits to amodulated symbol. The QAM constellations can be specified by cosine andsine coefficients in quadrature.

The tone mapping block 314 maps or assigns each data symbol to one ormore of the sub-carriers, known as tone mapping. The data symbols areprovided to the Inverse Fast Fourier Transform (IFFT) block 315 totransform the data symbols to the assigned sub-carriers in time domain.Other types of inverse Fourier transforms can be performed in otherexamples. The output from the IFFT block 315 are OFDMA waveforms in timedomain, in parallel for each STA. The cyclic prefix generator 316 adds acyclic prefix to the OFDMA waveforms. The parallel to serial converter(P/S) 317 converts the parallel OFDMA waveforms of multiple STAs into aserial digital signal. The serial digital signal is converted by adigital-to-analog converter 318 to an analog signal, which istransmitted via an antenna 152. The transmission that is transmitted viathe antenna 152 can include the preamble (which can have one or morecoded/modulated fields as described in greater detail herein) and thecoded/modulated data.

Reference is now made to FIG. 3B, which illustrates a receiver 320 fordemodulating each received OFDMA signal in accordance with an exampleembodiment. In some examples, the receiver 320 may be included withineach STA 102 to decode the received OFDMA signal from the DLtransmission of the AP 101. In some examples, the receiver 320 may beincluded within the AP 101 to decode received OFDMA signals from the ULtransmission of the STAs 102. As illustrated in FIG. 3B, the receiver320 includes an antenna 152, an analog-to digital converter (ADC) 322, acyclic prefix removal block 323, a fast fourier transform (FFT) block324, and a plurality of receiving (Rx) paths 325(1) to 325(Z)(generically referred to as Rx path 325) on which data is received andthe desired data is recovered. For DL transmission, only one receivingpath corresponding to one STA 102 needs to be processed by the receiver320 of the corresponding STA 102. For UL transmission, all of thereceiving paths, corresponding to all STAs 102, can be processed by thereceiver 320 of the AP 101.

The antenna 152 of the receiver 320 receives analog signals fromwireless communication frequency channels, such as from the transmitter310 as shown in FIG. 3A. The ADC 322 converts each received analogsignal into a digital signal. The cyclic prefix removal block 323removes a cyclic prefix from the digital signal. The FFT block 324 thentransforms the cyclic prefix removed digital signal in time domain intodata symbols. The data symbols for each STA 102 from the FFT block 324are processed on a respective one of the plurality of Rx paths. Forclarity, one Rx path 325(1) is indicated by a dashed box. One Rx path325 will now be described in detail. Data symbols are provided to achannel equalizer 326 for equalization, which may help to reduceinter-symbol interference (ISI) and noise effects for betterdemodulation. The equalized data symbols from the channel equalizer 326are input to the symbol demodulator 328. The symbol demodulator 328 usessymbol demodulation to demodulate the data symbols into series of bitsfor the STA 102 to recover the data. The receiver 320 can receive andinterpret the preamble of the received signals. When the preamble hasone or more coded or modulated fields (as described in greater detailherein), the receiver 320 can be used to decode or demodulate thepreamble.

In UL direction, a transmission including a preamble and payload data istransmitted from each associated STA 102 to the AP 101, in response tothe STA 102 receiving a trigger frame. The trigger frame can includeresource allocation information of one or more RUs for the payload dataof each associated STA 102. In some examples, at least one of the fieldsof the trigger frame is coded by the transmitter 310. After each STA 102receives the trigger frame, the STA 102 (having the transmitter 310) cantransmit a PPDU containing a preamble and payload data of the STA 102over one or more sub-carriers using the received resource allocationinformation, and modulate the data symbols over the one or moresub-carriers of the one or more RUs. The AP 101 (having the receiver320) can receive and interpret the transmission from the STAs, whichinclude a preamble and OFDMA signals of the payload data. When thepreamble has one or more coded fields (as described in greater detailherein), the receiver 320 can be used to decode the preamble.

Referring to FIG. 3A, in some examples the transmitter 310 includes aCyclic Shifter 330, which can be used to perform cyclic shifting, intime domain, on at least part of the preamble or the data payload. Thecyclic shifting can be performed after the IFFT block 315 and prior tothe Cyclic Prefix Generator 316. Similarly, the receiver 320 can includea Cyclic Shifter 332 for reversing, in time domain and prior to the FFT324, the cyclic shifting that was performed by the Cyclic Shifter 330 ofthe transmitter 310. In other example embodiments, there is no CyclicShifter 330 or Cyclic Shifter 332.

In some examples, shown in FIG. 3A, the transmitter 310 includes acoding block 334 for coding the data bits, to generate coded data bitsthat are then input to the symbol modulator 312. Examples of the codingblock 334 include block convolutional code (BCC) coding, repeat coding,interleaving, or scrambling. In some examples, shown in FIG. 3B, thereceiver 320 includes a decoding block 336 for decoding any coded databits after the symbol de-modulator block 328, to generate the originaldata bits. The decoding block 336 can include BCC decoding, repeatdecoding, deinterleaving, or descrambling. In other example embodiments,there is no coding block 334 or decoding block 336.

Example embodiments relate to a control signal that enables automaticwireless network version detection of a transmission, so that thewireless network version can be used for interpreting signalinginformation of the transmission and decoding of the payload of thetransmission. In some example embodiments, the control signal is withina preamble of the transmission. The wireless network version can be anIEEE 802.11 version, such as proposed IEEE 802.11be. The control signalis compatible with legacy systems and can indicate the legacy signalinginformation by way of a Legacy Signal (SIG) (L-SIG) field.

Some examples of legacy signaling from earlier versions of IEEE 802.11will now be described in greater detail. The legacy signaling can beincluded into the control signal (e.g., the preamble) of exampleembodiments, so as to be backwards compatible.

FIG. 4A illustrates an Orthogonal Frequency-Division Multiplexing (OFDM)Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU)400 according to IEEE 802.11a/g. Information specified in each field isin the frequency domain. In IEEE 802.11a/g, OFDM modulation is appliedto the desired signal over the sub-carrier signals by taking a 64-pointIFFT over 20 MHz bandwidth (sub-carrier spacing 312.5 kHz) to generateone OFDM symbol in the time domain with a guard interval added as acyclic prefix. The duration of each OFDM symbol is 4 microseconds (μs).

The PPDU 400 in FIG. 4A includes a Preamble 402 and a Data field 404.The Data field 404 is the payload data. The Preamble 402 includes ShortTraining field (STF) 406, Long Training field (LTF) 408, and Signaling(SIG) field 410, all of which are defined by the IEEE 802.11a PPDUformat.

The STF 406 is for signal detection, Automatic Gain Control (AGC),discovery selection, coarse frequency offset estimation, and timingsynchronization. The STF 406 includes two OFDM symbols.

The LTF 408 is for more accurate timing synchronization, more accurateestimate of frequency offset, and frequency channel estimation. The LTF408 includes two OFDM symbols.

The SIG field 410 is an indication of the length and transmission rateof the PHY service data unit (PSDU). The SIG field 410 is coded withcode rate 1/2 block convolutional code (BCC) and is modulated using BPSKmodulation. One OFDM symbol is used for transmission of the SIG field410.

FIG. 4B illustrates the SIG field 410 of the OFDM PPDU 400 of FIG. 4Aaccording to IEEE 802.11a. As shown in FIG. 4B, the SIG field 410includes total 24 bits, as follows (bit positions are denoted with “b”).

Rate subfield 412 (b0-b3) represents transmission rate in the 20 MHzbandwidth.

Reserved subfield 414 (b4) is reserved. It shall be set to 0 on transmitand ignored on receive.

Length subfield 416 (b5-b16) is a 12-bit integer that indicates the PSDUlength in octets.

Parity subfield 418 (b17) is a positive parity (even parity) bit forbits 0-16.

Tail subfield 420 (b18-b23) refers to tail bits, set to all zeros, toterminate the state of the BCC and used for the SIG field 410 encoding.

FIG. 4C illustrates a method 450 of encoding the SIG field 410 of FIG.4B according to IEEE 802.11a/g. The method 450 can be performed by thetransmitter 310. The SIG field 410 has 24 bits. At step 452, thetransmitter 310 encodes the SIG field 410 with code rate 1/2 blockconvolutional code (BCC), to a coded SIG of 48 bits. At step 454, thesymbol modulator 312 of the transmitter 310 modulates the coded SIGusing BPSK modulation to 48 data sub-carriers. At step 456, the tonemapping block 314 of the transmitter 310 performs tone mapping of theBPSK modulated SIG over 64 sub-carriers. At step 458, the IFFT block 315of the transmitter 310 then applies OFDM modulation over the 64sub-carrier signals in accordance with the tone mapping, by taking a64-point IFFT, arriving at a SIG symbol.

The detection of the IEEE 802.11a/g PPDU 400 includes detectingtransmitted signal strength in the Preamble 402 and a check on thesingle bit of the Parity subfield 418 in the SIG field 410. The Ratesubfield 412 in the SIG field 410 can be used differentiate between anIEEE 802.11g PPDU and an IEEE 802.11a PPDU.

Continuing through the IEEE 802.11 standard versions, other exampleindicators for automatic detection of wireless network type are definedby IEEE 802.11n (HT-mixed) and IEEE 802.11ac (VHT), not shown here.

For IEEE 802.11ax, FIG. 5 illustrates an OFDM High Efficiency (HE) PPDU500 according to IEEE 802.11ax. The prefix “L” indicates Legacy. TheL-STF subfield 502 and L-LTF subfield 504 are the same as defined byIEEE 802.11a in the legacy OFDM PPDU 400 (FIG. 4A). The PPDU 500 alsoincludes a L-SIG field 506, a Repeated L-SIG field 508, HE Signalingfields 510, Data 512, and Packet Extension (PE) 514.

The L-SIG field 506 follows the same format as the SIG field 410 shownin FIG. 4B, the Rate subfield 412 is set to 6 Mb/s (i.e., bit positionsb0b1b2b3=“1101” to represent 6 Mb/s); the Length subfield 416 is set tobe a value which is not divisible by 3; the Reserved subfield 414 is setto 0; the Parity subfield 418 is set to even parity of bits 0-16 and theTail subfield 420 is set to 0.

The RL-SIG field 508 in the PPDU 500 is a repeat of the L-SIG field 506and is used in IEEE 802.11ax to distinguish the HE PPDU 500 from anon-HT PPDU, HT PPDU and VHT PPDU.

In IEEE 802.11ax, automatic detection of the wireless network version ofthe HE PPDU 500 is performed based on at least detection of repetitionbetween L-SIG symbol carrying L-SIG field 506 and RL-SIG symbol carryingRL-SIG field 508 and decoding of Rate subfield 412 and Length subfield416 information in L-SIG field 506. The procedure for automaticdetection of HE PPDU 500 for an HE receiver (e.g., using receiver 320)is as follows:

-   -   Firstly: Detect the first symbol after L-LTF subfield 504.        Determine whether Quadrature Binary Phase Shift Keying (QBPSK)        is used in this symbol. If the first symbol after L-LTF subfield        504 is BPSK modulated, detect the RL-SIG field 508;    -   Secondly: Detect the second symbol after L-LTF and determine        whether the first and second symbols after L-LTF subfield 504        are the same. If detection of L-SIG field 506 repetition fails,        detect SIG for non-HT, HT and VHT and determine preamble types.        If repetition of L-SIG field 506 is detected in the RL-SIG field        508, the receiver 320 combines the L-SIG symbol carrying L-SIG        field 506 and the RL-SIG symbol carrying RL-SIG field 508,        decodes the combined signals, checks the Parity subfield 418 and        determine whether Rate subfield 412 is set to 6 Mbps. If Parity        subfield 418 or Rate subfield 412 check fails, determine        preamble types for non-HT, HT or VHT. If Parity subfield 418 and        Rate subfield 412 are valid, the receiver 320 evaluates the        Length subfield 416 in L-SIG field 506.    -   Thirdly: Determine, from the Length subfield 416, Length mod 3.        If Length mod 3 equals 0, detect SIG for non-HT, HT and VHT and        determine preamble types; if Length mod 3 equals 1, detect        HE-SIG-A and determine the HE PPDU mode.

Having described some existing IEEE standards for automatic detection ofthe wireless network version, example embodiments for automaticdetection of a wireless network version will now be described. Exampleembodiments include the generating of a control signal, such as thepreamble or the trigger frame, for a transmission. In some examples, thepreamble is an EHT preamble of proposed IEEE 802.11be. The automaticdetection of wireless network version type of the PPDU can be achievedwith an identifier, which can be an identifier symbol, an identifierfield or subfield, or other types of identifiers. The identifier symbolcan be defined by the identifier field or subfield, or by the encodingor modulation performed on the identifier field or subfield to arrive atthe identifier symbol. In some examples, an identifier symbol isgenerated from at least part of, but is not identical to, the L-SIGsymbol. In other examples, an identifier field or subfield is separatefrom the L-SIG field and the RL-SIG field.

FIG. 6 illustrates an example of an OFDM PPDU 600 having auto-detectablewireless network version indication, in accordance with an exampleembodiment. The PPDU 600 includes an identifier field which is differentthan the RL-SIG, denoted Partial Repeated Legacy Signal (SIG) (PRL-SIG)field 608. The L-STF subfield 602 and L-LTF subfield 604 are the same asdefined by IEEE 802.11a in the legacy OFDM PPDU 400 (FIG. 4A). The PPDU600 can include a SIG field particular to signaling information of theindicated wireless network version, such as EHT-SIG in this example. TheEHT-SIG and the payload data are collectively referred to as EHT-SIG andData 610.

In IEEE 802.11ax, RL-SIG is a fully repeated version of L-SIG 606including Rate (which is set to “1101” to indicate a fixed code rate of6 Mbps), Parity and Length which are used jointly for automaticdetection IEEE 802.11ax. The Length is also used for calculation of thenumber of OFDM symbols in the data transmission in the PPDU. FIG. 6illustrates, instead of the RL-SIG field of IEEE 802.11ax, a differentindicator denoted partial RL-SIG (PRL-SIG) field 608.

In the example PPDU 600 of FIG. 6 , using the same definition as in IEEE802.11ax, the Rate in the L-SIG is also set to “1101” to indicate afixed code rate of 6 Mbps. In IEEE 802.11ax, a single Parity bit in theSIG may be used for error detection, but can cause an error detectionproblem in lower signal-to-noise (SNR) conditions. The Rate subfield isset to a known value in the L-SIG in IEEE 802.11ax, and is known by thereceiver 320 to be 6 Mbps once the wireless network version is known.

In the PPDU 600, at least Cyclic Redundancy Check (CRC) is used for theerror detection. In the PRL-SIG field 608, the CRC is at the samecorresponding subfield location (bit positions) as the Rate subfielddefined in L-SIG 606. The bits in the remaining subfields defined inL-SIG 606 are repeated or partially repeated in the PRL-SIG field 608.In some examples, some bits of the remaining subfields defined in L-SIG606 are different in the PRL-SIG field 608.

In an example embodiment, automatic detection of the PPDU 600 of FIG. 6is conducted based on a CRC check, or in other examples, a combinationof the CRC check plus a Parity check. In some examples, the PRL-SIGfield 608 of FIG. 6 is modulated by the symbol modulator 312 using BPSKmodulation. Automatic detection can further be conducted by recognitionof the PRL-SIG field 608 as being modulated using BPSK modulation.

FIG. 7 illustrates an example embodiment of the PRL-SIG field 700,introduced in FIG. 6 as PRL-SIG field 608. The PRL-SIG field 700 is anidentifier field for automatic detection of the wireless networkversion. In the PRL-SIG field 700 of FIG. 7 , the subfields include theCRC subfield 702, Reserved (R) subfield 704, Length subfield 706, Parity(P) subfield 708, and Tail subfield 710. In this example embodiment ofthe PRL-SIG field 700, the 4 CRC bits and 6 Tail bits can be codedtogether using a code rate 1/2 BCC encoder, which is the same type ofBCC encoder as used for L-SIG 606. The CRC in the CRC subfield 702protects the Rate (i.e., bit positions b0-b3) and Length (i.e., b5-b16)in the L-SIG 606.

FIG. 8 illustrates an example method 800 of encoding the PRL-SIG field700 of FIG. 7 . In an example embodiment, the method 800 can beperformed by the transmitter 310 (FIG. 3A). At step 802, the transmitter310 performs segment parsing of the PRL-SIG field 700 to a first groupof bits and a second group of bits. The first group of bits is the CRCsubfield 702 and Tail subfield 710, and the second group of bits is theReserved (R) subfield 704, Length subfield 706, and Parity (P) subfield708. At step 804, the transmitter 310 encodes the CRC and Tail using acode rate 1/2 BCC encoder. At step 806, the transmitter 310 duplicatesthe coded Reserved, Length, and Parity bits generated in L-SIG. At step808, the transmitter 310 constructs together the coded bits from thefirst group of bits and the second group of bits and sends theconstructed coded bits to the symbol modulator 312 (FIG. 3A) for BPSKmodulation.

FIG. 9 illustrates an example method 900 of detection of the PRL-SIGfield 700 from the signal generated by the method 800 of FIG. 8 . At thereceiver 320, a signal (PPDU) in time domain is received and the FFTblock 324 of the receiver 320 performs Fast Fourier Transform to recovercoded bits of the PRL-SIG field 700. At step 902, the receiver 320detects the repetition of Reserved (R) subfield 704, Length subfield706, and Parity (P) subfield 708 from the PRL-SIG field 700, bycomparing with the corresponding coded bits in L-SIG. At step 904, thereceiver 320 performs segment parsing of the received coded PRL-SIG to afirst group of bits and a second group of bits. The first group of bitsis the coded CRC subfield 702 and Tail subfield 710 and the second groupof bits is the coded Reserved subfield 704, Length subfield 706, andParity subfield 708. At step 906, the receiver 320 performs code rate1/2 BCC decoding on the first group of bits to generate the decoded bitsof the CRC. At step 908, the receiver 320 combines the second group ofbits with coded L-SIG subfields Rate, Reserved, Length, Parity, andTail, the combination of which at step 910 is decoded using code rate1/2 BCC decoding to generate the decoded bits of Rate, Length andParity.

In an example, the receiver 320 can conduct a CRC check, using thedecoded bits of CRC, onto the protected Rate and Length subfields(decoded from the L-SIG and the PRL-SIG). If the CRC check passes, thereceiver determines the PPDU to be a specified wireless network version,such as IEEE 802.11be. In other examples, the check is a combination ofa CRC check, and a Parity check with the L-SIG.

FIG. 10 illustrates another example method 1000 of encoding the PRL-SIGfield 700 of FIG. 7 . The format of the PRL-SIG field 700 in thisexample is the same as shown in FIG. 7 . However, in the method 1000 ofFIG. 10 , the encoding for the CRC is different than in FIG. 8 . In themethod 1000, the CRC bits are coded by coding block 334 with a code rate1/2 tail biting BCC encoder. The tail biting BCC encoder does not usethe tail bits of the Tail subfield 710 (FIG. 7 ). The CRC protects theRate (i.e., bit positions b0-b3) and Length (i.e., b5-b16) of the L-SIG.

In the method 1000 of FIG. 10 , at step 1002 the transmitter 310performs segment parsing of the PRL-SIG field 700 to a first group ofbits and a second group of bits. The first group of bits is the CRCsubfield 702, and the second group of bits is the Reserved subfield 704,Length subfield 706, Parity subfield 708, and Tail subfield 710. At step1004, the transmitter 310 encodes the CRC with the tail biting BCCencoder, which does not use the Tail bits. At step 1006, the transmitter310 duplicates the coded Reserved, Length, Parity, and Tail generated inL-SIG. At step 1008, the transmitter 310 constructs together the codedbits from the first group of bits and the second group of bits and sendsthe constructed 48 coded bits to the symbol modulator 312 (FIG. 3A) forBPSK modulation.

FIG. 11 illustrates an example method 1100 of detecting the codedPRL-SIG field 700 from the signal generated by the method 1000 of FIG.10 . Generally, the receiver 320 can perform detection of the CRC in thePRL-SIG field 700 and the Length and Parity in both the L-SIG andPRL-SIG. At the receiver 320, a signal (PPDU) in time domain is receivedand the FFT block 324 of the receiver 320 performs Fast FourierTransform to recover coded bits of the PRL-SIG field 700. At step 1102,the receiver 320 detects the repetition of Reserved, Length, Parity andTail in the coded bits of the PRL-SIG field 700. At step 1104, thereceiver 320 performs segment parsing of the received coded PRL-SIGfield 700 to a first group of bits and a second group of bits. The firstgroup of bits is the coded CRC subfield 702 and a second group of bitsis the coded Reserved, Length, Parity and Tail. At step 1106, thereceiver 320 performs code rate 1/2 tail biting BCC decoding on thefirst group of bits to generate the decoded bits of the CRC. At step1108, the receiver 320 combines the second group of bits with codedL-SIG subfields Rate, Reserved, Length, Parity, and Tail, thecombination of which at step 1110 is decoded using code rate 1/2 BCCdecoding to generate the decoded bits of Rate, Length and Parity.

In an example, the receiver 320 can conduct a CRC check onto theprotected Rate and Length subfields (from the L-SIG and/or the PRL-SIG).If the CRC check passes, the receiver 320 determines the PPDU to be aspecified wireless network version, such as IEEE 802.11be. In otherexamples, the check is a combination of the CRC check, and a Paritycheck with the L-SIG.

FIG. 12 illustrates a second example embodiment of the PRL-SIG field1200, introduced in FIG. 6 as PRL-SIG field 608, and includes the CyclicRedundancy Check (CRC). The PRL-SIG field 1200 is an identifier fieldfor automatic detection of the wireless network version. In thisexample, the subfields in the PRL-SIG field 1200 include a 3-bit CRCsubfield 1202 which protects the Length subfield, i.e., bit positionsb5-b16 in L-SIG. The PRL-SIG field 1200 also includes a CRC Repeatsubfield 1204. In the CRC Repeat subfield 1204, the CRC bits from CRCsubfield 1202 repeat twice and the repeated CRC bits are located in bitpositions b18-b23. The CRC protects the Rate subfield (i.e., b0-b3) andLength subfield (i.e., b5-b16) in L-SIG. In other examples, rather thanrepeating twice, the CRC bits in CRC Repeat subfield 1204 repeat once orrepeat more than twice.

FIG. 13 illustrates an example method 1300 of encoding the PRL-SIG field1200 of FIG. 12 . In an example embodiment, the method 1300 can beperformed by the transmitter 310 (FIG. 3A). At step 1302, thetransmitter 310 performs segment parsing of the PRL-SIG field 1200 to afirst group of bits and a second group of bits. The first group is theCRC subfield 1202 and CRC Repeat subfield 1204, and the second group ofbits is the Rate subfield (1 bit at b3), Reserved subfield, Lengthsubfield, and Parity subfield. At step 1304, the transmitter 310 encodesthe first group of bits containing the CRC using 2× repetition coding.At step 1306, the transmitter 310 duplicates the coded Rate (1 bit),Reserved, Length, and Parity generated in L-SIG bits. At step 1308, thetransmitter 310 constructs together the coded bits from the first groupof bits and the second group of bits and sends the constructed 48 codedbits to the symbol modulator 312 (FIG. 3A) for BPSK modulation.

FIG. 14 illustrates an example method 1400 of receiving and detectingthe coded PRL-SIG field 1200 from the signal generated by the method1300 of FIG. 13 . The receiver 320 can perform detection of the CRC inthe PRL-SIG field 1200, and perform detection of the Length and Parityin both L-SIG and PRL-SIG.

At the receiver 320, a signal (PPDU) in time domain is received and theFFT block 324 of the receiver 320 performs Fast Fourier Transform torecover coded bits of the PRL-SIG field 1200. At step 1402, the receiver320 detects repetition of the Reserved, Length, and Parity in the codedbits of the PRL-SIG field 1200. At step 1404, the receiver 320 performssegment parsing of the received coded PRL-SIG field 1200 to a firstgroup of bits and a second group of bits. The first group of bits is therepetition coded CRC (which were originally coded from the CRC subfield1202 and CRC Repeat subfield 1204 of the PRL-SIG 1200). The second groupof bits is the coded Rate (1 bit) subfield, Reserved subfield, Lengthsubfield, Parity subfield, which were originally coded from the PRL-SIG1200. At step 1406, the receiver 320 performs repetition decoding on thefirst group of bits to generate the decoded bits of the CRC. At step1408, the receiver 320 combines the second group of bits with codedL-SIG subfields Rate, Reserved, Length, Parity, and Tail, thecombination of which at step 1410 is decoded using code rate 1/2 BCCdecoding to generate the decoded bits of Rate, Length and Parity.

After detection and decoding of CRC, Rate, Length, and Parity subfieldsas shown in FIGS. 9, 11 and 14 , the receiver 320 can conduct a CRCcheck (or combination of CRC check and Parity check) onto the protectedRate and Length subfields (from PRL-SIG and L-SIG). If the CRC check (orcombination of CRC check and Parity check) passes, the receiverdetermines the PPDU to be a specified wireless network version, such asIEEE 802.11be. Otherwise, the receiver 320 can further detect whetherthe PPDU is an IEEE 802.11ax PPDU, or other PPDU types.

FIG. 15 illustrates another example embodiment of the PRL-SIG field1500, introduced in FIG. 6 as PRL-SIG field 608, in which the PRL-SIGfield 1500 has a Flag subfield 1502. The PRL-SIG field 1500 is anidentifier field for automatic detection of the wireless networkversion. The PRL-SIG field 1500 includes a Reserved subfield 1504, aLength subfield 1506, a Parity subfield 1508, and a Tail subfield 1510.As defined in IEEE 802.11ax and proposed IEEE 802.11be, the Rate in theL-SIG is set to “1101” to indicate a fixed rate of 6 Mbps. An exampleembodiment of the PPDU 600 includes the partial RL-SIG (PRL-SIG) field1500 which is subsequent to the L-SIG. Because the Rate subfield of theL-SIG is set to a known value in the L-SIG, the Rate does not need to beverified by the receiver 320. Therefore, in the PRL-SIG field 1500, theRate subfield defined in L-SIG can be (at least partially) differentthan the PRL-SIG field 1500, with a Flag subfield 1502 at the samecorresponding subfield location (corresponding bit positions). Theremaining bits in the remaining subfields defined in L-SIG can berepeated in the PRL-SIG field 1500 in an example. The Flag 1502 is setto a predefined value which is different from “1101” to indicate thespecified wireless network version of the PPDU, such as IEEE 802.11be orfuture amendments. Various different flags can each represent adifferent wireless network version in some examples.

The PRL-SIG field 1500 of FIG. 15 includes a Flag subfield 1502 of 4bits and Tail subfield 1510 of 6 bits. For encoding of the PRL-SIG field1500 of FIG. 15 , the Flag subfield 1502 and the Tail subfield 1510 arecoded together by the coding block 334 using a code rate 1/2 BCC encoder(e.g., the same type of BCC encoder as used for L-SIG). The generationof the coded PRL-SIG 1500 from FIG. 15 is similar to the method 800 ofgenerating the coded PRL-SIG as illustrated in FIG. 8 , by replacing“CRC” with “Flag”.

At the receiver 320, detection and interpreting Flag subfield 1502 inthe PRL-SIG field 1500 and the Length and Parity in both L-SIG field andPRL-SIG field 1500 are similar to the method 900 of detecting andinterpreting of the coded PRL-SIG as shown in FIG. 9 , by replacing“CRC” with “Flag”.

Another example format of the PRL-SIG will now be described, not shown.The format of the PRL-SIG in this example is the same as the PRL-SIG1500 as shown in FIG. 15 . In the example PRL-SIG, the encoding for theFlag is different than the PRL-SIG field 1500. The bits of the Flagsubfield 1502 are coded with a code rate 1/2 tail biting BCC encoder. Atail biting convolutional code does not require tail bits fortermination. Generation of the coded PRL-SIG is similar to the method1000 for generation of the coded PRL-SIG 700 as illustrated in FIG. 10 ,by replacing “CRC” with “Flag”. At the receiver 320, detection andinterpreting of Flag in the example PRL-SIG and the Length and Parity inboth L-SIG and PRL-SIG are similar to the method 1100 of receiving andinterpreting the PRL-SIG 700 as illustrated in FIG. 11 , by replacing“CRC” with “Flag”.

FIG. 16 illustrates another example embodiment of the PRL-SIG field1600, introduced in FIG. 6 as PRL-SIG field 608. The PRL-SIG field 1600is an identifier field for automatic detection of the wireless networkversion. The PRL-SIG field 1600 includes a Flag subfield 1602, RepeatedRate subfield 1604, Reserved subfield 1606, Length subfield 1608, Paritysubfield 1610, and Flag Repeat subfield 1612. The subfields in thePRL-SIG field 1600 include a 3-bit Flag subfield 1602, which is repeatedtwice and the repeated bits are located into the Flag Repeat subfield1612 (bit positions b18-b23) of the PRL-SIG field 1600. In otherexamples, the Flag subfield 1602 is repeated once, or more than twice,in the Flag Repeat subfield 1612.

The method of generation of coded PRL-SIG 1600 from FIG. 16 is similarto the method 1300 of generating the coded PRL-SIG 1200 as illustratedin FIG. 13 , by replacing “CRC” with “Flag”.

At the receiver 320, detection and interpreting of Flag subfield 1602 inPRL-SIG field 1600 and the Length and Parity in both L-SIG and PRL-SIGfield 1600 are similar to the method 1400 of receiving and interpretingas shown in FIG. 14 , by replacing “CRC” with “Flag”.

After detection and decoding of Flag, Rate, Length, and Parity subfieldsas stated above, similar to a HE receiver, the receiver 320 can checkwhether Rate, Length and Parity are valid by comparing to L-SIG asdefined in IEEE 802.11ax. If Rate, Length and Parity are valid, thereceiver 320 further checks Flag. If Flag is valid, the receiver 320determines the PPDU is a specified wireless network version such as IEEE802.11be PPDU. Otherwise the PPDU is the HE PPDU. If Rate, Length orParity is not valid, the receiver 320 can detect other legacy PPDUtypes.

Reference is now made to FIGS. 17A, 17B, 17C, 17D, 17E. In FIG. 17E, inan example embodiment, the auto-detection of the wireless networkversion of the PPDU can be provided by an Identifier 1710. FIGS. 17A,17B, 17C, 17D illustrate various example embodiments of an OFDM PPDUhaving the Identifier 1710, for indicating both the Physical Layer (PHY)version and the frame-type of the OFDM PPDU.

The Identifier 1710 can be a field or a subfield of the PPDU, and iscontained within the PHY header (preamble). The Identifier 1710 has aPHY Version Identifier 1712. The PHY Version Identifier 1712 can be usedto indicate the wireless network version, e.g. IEEE 802.11 version or anamendment version. This allows for extensibility of the auto-detectionmethod for IEEE 802.11be and future versions or standards. TheIdentifier 1710 also indicates the frame format type, referred to hereinas a Frame Type Identifier 1714. The Frame Type Identifier 1714 canidentify frame types such as MU, SU, TB or ER SU PPDU. The Frame TypeIdentifier 1714 can be used to identify any other possible frame typeand future frame types.

In various examples, the Identifier 1710 is greater than 4 bits, greaterthan 10 bits, equal to 8 bits, or equal to 10 bits. In an example, 3 to4 bits are used for the PHY Version Identifier 1712, and 6 to 7 bits areused for the Frame Type Identifier 1714 (totaling 10 bits in each case).FIGS. 17A, 17B, 17C, 17D show example locations of the Identifier 1710in a PPDU.

The number of symbols for the Identifier 1710 can be one symbol in anexample, or more than one symbol in other examples. In an exampleembodiment, the Identifier 1710 can be subsequent to the RL-SIG orL-SIG. In another example, the Identifier 1710 can be within the SIGfield particular to signaling information of the indicated wirelessnetwork version, such as an EHT-SIG field as a subfield type.

FIG. 17A illustrates a first example embodiment of the OFDM PPDU 1700,wherein the Identifier 1710 is a field that is separate from, andsubsequent to, the L-SIG and RL-SIG. In some examples, the Identifier1710 is transmitted after the L-SIG and the RL-SIG.

FIG. 17B illustrates a second example embodiment of the OFDM PPDU 1702,wherein the Identifier 1710 is a field that is subsequent to L-SIG, andthere is no RL-SIG in this example OFDM PPDU 1702. In some examples, theIdentifier 1710 is transmitted after the L-SIG.

FIG. 17C illustrates a third example embodiment of the OFDM PPDU 1704,wherein the Identifier 1710 is a subfield within a SIG field particularto signaling information of the indicated wireless network version, suchas EHT-SIG 1716 in this example. In the OFDM PPDU 1704, the Identifier1710 is a subfield within EHT-SIG 1716, and EHT-SIG 1716 is separatefrom, and subsequent to, L-SIG and RL-SIG. In some examples, theIdentifier 1710 subfield is transmitted after the L-SIG and the RL-SIG.

In the OFDM PPDU 1706 of FIG. 17D, the Identifier 1710 is a subfieldwithin the EHT-SIG 1716, and EHT-SIG 1710 is subsequent to L-SIG. Thereis no RL-SIG in the example PPDU 1706 of FIG. 17D. In some examples, theIdentifier 1710 subfield is transmitted after the L-SIG.

As shown in FIG. 17E, in an example embodiment, the Identifier 1710includes the PHY Version 1712 as a separate subfield (separate bits)from the Frame Type Identifier 1714. The Identifier 1710 includes afirst set of one or more bits that represent the PHY Version Identifier1712 of the transmission and a second set of one or more bits thatrepresent the Frame Type Identifier 1714 of the transmission. In anotherexample, not shown here, the Identifier 1710 includes at least someshared bits that represent both the wireless network version of thetransmission and the Frame Type Identifier 1714 of the transmission. Inother words, a predefined coding scheme, lookup table, specified policy,algorithm, etc., can be used to translate the bits of the Identifier1710 to each of the PHY Version Identifier 1712 and the Frame TypeIdentifier 1714.

In an example, not shown here, the Identifier 1710 can be within atrigger frame to solicit uplink transmission. In an example, not shownhere, the Identifier 1710 can be within a preamble of the uplinktransmission, having a field or subfield position similar to any one ofthe OFDM PPDU 1700, 1702, 1704, 1706.

FIG. 18A illustrates an example embodiment of an OFDM PPDU 1800 havingauto-detectable wireless network version indication using a differentversion of the RL-SIG, by way of an Interleaved RL-SIG (IRL-SIG) field1802. The IRL-SIG field 1802 is an identifier field for automaticdetection the wireless network version. The OFDM PPDU 1800 includes thesame L-STF, L-LTF and L-SIG fields that are defined by legacy standards.The OFDM PPDU 1800 can include one or more SIG fields particular tosignaling information of the indicated wireless network version, such asEHT Signaling Fields 1804 in this example. In the example OFDM PPDU1800, a different version of the L-SIG in the coded bit level is theIRL-SIG field 1802, in which an interleaved version of the coded bitsfrom the L-SIG is generated by re-arranging the order of bits from theL-SIG using a specified interleaver known by both the transmitter 310and the receiver 320. The IRL-SIG field 1802 is subsequent to the L-SIGfield in the OFDM PPDU 1800. In an example embodiment, the specifiedinterleaver can be predetermined. In an example embodiment, thespecified interleaver is particular to the wireless network version(e.g. EHT 802.11be, or other version).

In the OFDM PPDU 1800 of FIG. 18A, automatic detection of the specifiedwireless network version of the PPDU, e.g. IEEE 802.11be PPDU, isconducted based on a check by comparing L-SIG with the recovery of L-SIGfrom the IRL-SIG field 1802. The IRL-SIG field 1802 is represented inthe data sub-carrier level. In IRL-SIG field 1802, the data sub-carriersare obtained by interleaving the data sub-carriers of L-SIG.

FIG. 19 illustrates an example method 1900 of generating the IRL-SIGfield 1802 of the OFDM PPDU 1800 of FIG. 18A. At step 1902, thetransmitter 310 interleaves coded bits in L-SIG field with the specifiedinterleaver to generate the IRL-SIG field 1802. At step 1904 the codedbits of IRL-SIG field 1802 are BPSK modulated using the symbol modulator312. At step 1906, the tone mapping block 314 of the transmitter 310performs tone mapping of the BPSK modulated IRL-SIG. At step 1908, theIFFT block 315 of the transmitter 310 then applies OFDM modulation overthe sub-carrier signals in accordance with the tone mapping, byperforming an IFFT, arriving at an IRL-SIG symbol.

In an alternate example, step 1902 is performed after step 1904. Forexample, the transmitter 301 first performs BPSK modulation on theIRL-SIG (which is the same as L-SIG at this point). Then, thetransmitter 301 interleaves the BPSK modulated signals with a specifiedinterleaver, prior to or as part of the tone mapping by the tone mappingblock 314.

FIG. 20 illustrates an example method 2000 of receiving and detectingthe IRL-SIG field 1802 from the signal generated by the method 1900 ofFIG. 19 . At step 2002, at the receiver 320, a signal (PPDU) in timedomain is received and the FFT block 324 of the receiver 320 performsFourier Transform to recover coded bits, and observes the first symbolafter the L-SIG in the OFDM PPDU 1800 (FIG. 18 ). To determine whetherthe first symbol after the L-SIG is the IRL-SIG field 1802, at step2004, the receiver 320 performs deinterleaving of the recovered bits ofthe first symbol after the L-SIG. At step 2006, the receiver 320 checksthe recovered bits and compares the deinterleaved Rate, Reserved,Length, Parity and Tail recovered at step 2004 with the L-SIG. If thereis repetition detected in step 2006 between the recovered bits from step2004 and the L-SIG, at step 2008 the receiver 320 detects and concludesthat the PPDU is a specified wireless network version, e.g., IEEE802.11be in this example. If the check at step 2006 is not satisfiedbecause the first symbol is found to be merely RL-SIG (non-interleaved),at step 2010 a check is performed between the Rate, Reserved, Length,Parity and Tail of RL-SIG (which is the first symbol after L-SIG) andL-SIG. At step 2012 if the check at step 2010 is satisfied the receiverdetects the received PPDU as being an HE PPDU (802.11ax), or otherchecks are performed to determine whether the received PPDU is anotherwireless network type (which would be neither 802.11be nor 802.11ax).

The alternate path 2014 in FIG. 20 illustrates some instances where theHE PPDU (802.11ax) is checked separately from, or in parallel with, thedeinterleaving step 2004. At step 2002, the first symbol after L-SIG maybe RL-SIG. At step 2010, the receiver 320 checks the recovered bits bycomparing the Rate, Reserved, Length, Parity and Tail of the RL-SIG withthe L-SIG. At step 2012, if the check is satisfied, the receiver detectsthe PPDU as being an HE PPDU (802.11ax).

Alternatively, the receiver 320 checks the deinterleaved subcarriers ofthe first received symbol after L-SIG by comparing with the subcarriersof L-SIG. If there is repetition between the deinterleaved subcarriersof the first symbol after the L-SIG and the subcarriers of the L-SIG,the receiver detects and concludes that the PPDU is a specified wirelessnetwork version, e.g., IEEE 802.11be in this example. If the check isnot satisfied, a second repetition check is performed between thesubcarriers of the first symbol after the L-SIG and the subcarriers ofthe L-SIG. If the second repetition check between the subcarriers of thefirst symbol after the L-SIG and the subcarriers of the L-SIG issatisfied, the receiver detects and concludes that the received PPDU isan HE PPDU (802.11ax). If the second repetition check is not satisfiedbetween the subcarriers of the first symbol after the L-SIG and thesubcarriers of the L-SIG, other checks are performed to determinewhether the received PPDU is another wireless network type (which wouldbe neither 802.11be nor 802.11ax).

In an example embodiment, multiple different specified interleavers caneach respectively indicate a different wireless network version (PHYtype) to generate the IRL-SIG. The IRL-SIG is an indication of one of aplurality of possible PHY types. In an example, the receiver 320 can beconfigured to perform blind selection of different possible interleaversof the received transmission until the L-SIG is matched with therecovered L-SIG from the detected IRL-SIG field 1802. In examples, theblind selection can be performed in a specified order or in randomorder.

FIG. 18B illustrates an example embodiment of an OFDM PPDU 1820 havingauto-detectable wireless network version indication using a differentversion of the RL-SIG by way of a Scrambled RL-SIG (SRL-SIG) field 1822.The SRL-SIG field 1822 is an identifier field for automatic detection ofthe wireless network version. In the OFDM PPDU 1820, rather thaninterleaving as in FIG. 18A, the RL-SIG of a PPDU is modified byscrambling the L-SIG to generate a scrambled RL-SIG (SRL-SIG) field1822. A scrambling sequence or scrambling function is used to generatethe SRL-SIG field 1822. Referring to the OFDM PPDU 1800 of FIG. 18A, forexample, the SRL-SIG field 1822 in this OFDM PPDU 1820 instead of theIRL-SIG field 1802 of the OFDM PPDU 1800.

The OFDM PPDU 1820 can include one or more SIG fields particular tosignaling information of the indicated wireless network version, such asEHT Signaling Fields in this example. In an example embodiment, thespecified scrambling sequence can be predetermined. In an exampleembodiment, the specified scrambling sequence is particular to thewireless network version (e.g. EHT, or other version).

The generating and encoding of the OFDM PPDU 1820 of FIG. 18B by thetransmitter 310 can follow a similar method 1900 as in FIG. 19 , with ascrambling step using the specified scrambling sequence (or scramblingfunction) performed instead of the interleaving step 1902. The receivingand interpreting of the OFDM PPDU 1820 for auto-detection of thewireless network version by the receiver 320 can follow a similar method2000 as in FIG. 20 , with a descrambling step using the specifiedscrambling sequence (or descrambling function) performed instead of thedeinterleaving step 2004.

FIG. 21 illustrates an example of an OFDM PPDU 2100 havingauto-detectable wireless network version indication using a modifiedRL-SIG, denoted as Cyclic Shifted RL-SIG (CS-RL-SIG) field 2102, inaccordance with an example embodiment. The CS-RL-SIG field 2102 is anidentifier for automatic detection the wireless network version. Asshown in FIG. 21 , the OFDM PPDU 2100 keeps the L-STF, L-LTF and L-SIGsymbols unchanged. The RL-SIG symbol is the symbol after the L-SIGsymbol. A modification of the RL-SIG signal in the time domain isperformed, in which the RL-SIG signal in the time domain after the IFFTblock 315 is cyclic shifted before adding cyclic prefix (CP) by the CPgenerator 316. The cyclic shifting distance is known by both thetransmitter 310 and the receiver 320. At the coded bit level, theCS-RL-SIG 2102 is a repeat of the L-SIG 2104.

The receiver 320 can perform autodetection of the PPDU 2100 as being aspecified wireless network version, e.g., IEEE 802.11be, based a checkof the repetition of a shifted version of CS-RL-SIG 2102 compared withL-SIG 2104. In the OFDM PPDU 2100, the CS-RL-SIG 2102 is a cyclicshifted repeat L-SIG signal 2104 in the time domain. The CS-RL-SIGsignal is obtained by cyclic shifting, in the time domain, a RL-SIGsignal before adding cyclic prefix by cyclic prefix generator 316.

FIG. 22 illustrates an example method 2200 of generating and coding theCS-RL-SIG field 2102 shown in FIG. 21 . The method 2200 can be performedby the transmitter 310. At step 2202, the coded bits of L-SIG 2104 areBPSK modulated using the symbol modulator 312. At step 2204, the tonemapping block 314 of the transmitter 310 tone maps the BPSK modulatedL-SIG. At step 2206, the IFFT block 315 performs IFFT in accordance withthe tone mapping, arriving at a RL-SIG symbol in time domain withoutcyclic prefix. At step 2208, the Cyclic Shifter 330 performs cyclicshifting at a specified cyclic shifting distance known by both thetransmitter 310 and the receiver 320, to generate a CS-RL-SIG symbol. Atstep 2210, the cyclic prefix generator 316 adds a cyclic prefix to theCS-RL-SIG symbol.

Detecting and decoding the coded CS-RL-SIG field is performed by thereceiver 320 by, in time domain, removing the cyclic prefix byperforming cyclic shifting to reverse the cyclic shifting from themethod 2200 of FIG. 22 . After FFT by the FFT block 324, the recoveredfield from the coded CS-RL-SIG field 2102 is compared with the L-SIG2104, with a match being the indication of the specified wirelessnetwork version, e.g., IEEE 802.11be. Otherwise, another wirelessnetwork version or legacy version may be detected. In an example,multiple different specified cyclic shifting distances can eachrespectively indicate a different wireless network version (PHY type) togenerate the CS-RL-SIG.

FIG. 23 illustrates an example method 2300 for enabling automaticwireless network version detection within transmissions, in accordancewith an example embodiment. At step 2302, the transmitter 310 generatesa control signal for a transmission. In one example, the control signalincludes i) a Legacy Signal (SIG) (L-SIG) symbol and ii) an identifiersymbol which is generated from at least part of, but is not identicalto, the L-SIG symbol, the identifier symbol indicates a wireless networkversion of the transmission. In another example, the control signalincludes a Legacy Signal (SIG) (L-SIG) field, a Repeated L-SIG (RL-SIG)field, and an identifier separate from the L-SIG field and the RL-SIGfield, the identifier indicates i) a wireless network version of thetransmission and ii) a frame type of the transmission.

At step 2304, the transmitter 310 transmits the control signal. In someexamples, at step 2304 the transmitting of the control signal includestransmitting the identifier symbol after the L-SIG symbol. At step 2306,the receiver 320 receives the control signal. At step 2308, the receiver320 detects the wireless network version of the transmission from thecontrol signal. At step 2310, the receiver 320 interprets the controlsignal according to the detected wireless network version.

The described example embodiments of the control signal (preamble) forauto-detection of the wireless network version can be applied to uplinktransmission, not shown here. In an example, the control signal can bewithin a trigger frame to solicit uplink transmission. In an example,the control signal can be within a preamble of the uplink transmission.

FIG. 1C is a schematic diagram of an example wireless communicationdevice 130, in accordance with example embodiments. For example, thewireless communication device 130 may be the AP 101 or the STA 102, andmay include the transmitter 310 (FIG. 3A) or the receiver 320 (FIG. 3B).The wireless communication device 130 may be used for both Single User(SU) and multiple access communications within the wirelesscommunication system 100. Although FIG. 1C shows a single instance ofeach component, there may be multiple instances of each component in thewireless communication device 130 and the wireless communication device130 could be implemented using parallel and distributed architecture.Some of the components in FIG. 1C are optional in some examples.

The wireless communication device 130 may include one or more processingdevices 132, such as a processor, a microprocessor, anapplication-specific integrated circuit (ASIC), a field-programmablegate array (FPGA), a dedicated logic circuitry, or combinations thereof.The wireless communication device 130 may also include one or moreoptional input/output (I/O) interface(s) 134, which may enableinterfacing with one or more optional input devices 148 and outputdevices 150. The wireless communication device 130 may include one ormore network interfaces 136 for wired or wireless communication with anetwork (e.g., an intranet, the Internet, a Peer-to-Peer (P2P) network,a Wide Area Network (WAN), a wireless WAN (WWAN), a Local Area Network(LAN), or a Radio Access Network (RAN)) or other node. Wireless networksmay make use of wireless connections transmitted over an antenna 152.The network interface(s) 136 may provide multiple access wirelesscommunication via one or more transmitters or transmit antennas and oneor more receivers or receive antennas, for example. In this example, oneantenna 152 is shown, which may serve for multiple access transmission.However, in other examples there may be multiple antennas fortransmitting and receiving. In some examples, an antenna array may beused. The wireless communication device 130 may also include one or morestorage units 138, which may include a mass storage unit such as a solidstate drive, a hard disk drive, a magnetic disk drive or an optical diskdrive.

The wireless communication device 130 may include one or morenon-transitory memories 140 that can include physical memory 142, whichmay include a volatile or non-volatile memory (e.g., a flash memory, arandom access memory (RAM), or a read-only memory (ROM)). The memory 140(as well as storage unit(s) 138) may store instructions for execution bythe processing device(s) 132, such as to carry out processing such asthose described in the present disclosure. The memory 140 may includeother software instructions, such as for implementing an operatingsystem (OS), and other applications/functions. In some examples, one ormore data sets or modules may be provided by an external memory (e.g.,an external drive in wired or wireless communication with the wirelesscommunication device 130) or may be provided by a transitory ornon-transitory computer-readable medium. Examples of non-transitorycomputer readable media include a RAM, a ROM, an erasable programmableROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flashmemory, a CD-ROM, or other portable memory storage.

In some examples, there may be a bus 144 providing communication amongcomponents of the wireless communication device 130. The bus 144 may beany suitable bus architecture including, for example, a memory bus, aperipheral bus or a video bus. Optional input device(s) 148 (e.g., akeyboard, a mouse, a microphone, a touchscreen, or a keypad) andoptional output device(s) 150 (e.g., a display, a speaker or a printer)are shown as external to the wireless communication device 130, andconnected to optional I/O interface(s) 134. In other examples, one ormore of the input device(s) 148 or the output device(s) 150 may beincluded as a component of the wireless communication device 130.

The transmitter 310 and the receiver 320 may be included as one or morecomponents of the wireless communication device 130. For example, thetransmitter 310 and the receiver 320 may be included as a singlecomponent for transmitting and receiving radio frequency (RF) analogsignals. In other examples, the transmitter 310 and the receiver 320 maybe included as two separate components for transmitting and receivingradio frequency (RF) analog signals respectively. The transmitter 310may provide transmission of PPDUs and the receiver 320 may receive thePPDU.

When the wireless communication device 130 is the AP 101, communicationwith selected or associated STAs 102 can be performed using the antenna152. The processing device 132 may carry out the steps and functionsdescribed herein. When the wireless communication device 130 is a STA102, communications with the AP 101 can be performed via the antenna152.

The wireless communication device 130 also includes a power supply block146 to supply power to the wireless communication device 130. In someexamples, the power supply block 146 can include a battery. In someexamples, the power supply block 146 includes a power adapter (e.g.,AC/DC or DC/DC) for connection to an external power source and can beused for charging the battery.

In at least some examples, instructions that cause the processing device132 to carry out methods in accordance with example embodiments arestored in storage unit(s) 138 or memory 140 of the wirelesscommunication device 130. In some examples, the processing device 132may be one or more controllers, which may comprise a modulator or aprocessor. Example systems and methods described herein, in accordancewith examples, can be implemented by the one or more controllers. Theone or more controllers can comprise hardware, software, or acombination of hardware and software, depending on the particularcomponent and function. In some examples, the one or more controllerscan include analog or digital components, and can include one or moreprocessors, one or more non-transitory storage mediums such as memorystoring instructions executable by the one or more processors, one ormore transceivers (or separate transmitters and receivers), one or moresignal processors (analog or digital), and one or more analog circuitcomponents.

Example embodiments can applied to MU communication, single user (SU)communication, trigger based (TB) communication, or extended range (ER)TB communication.

An example embodiment is a non-transitory computer-readable medium whichstores instructions that when executed by a processing device causes theprocessing device to perform any of the described methods, processes orfunctions.

The example embodiments described above may be implemented by usinghardware only or by using software and a necessary universal hardwareplatform. Based on such understandings, the technical solution of someexample embodiments may be embodied in the form of a software product.The software product may be stored in a non-volatile or non-transitorystorage medium, which can be a compact disk read-only memory (CD-ROM),Universal Serial Bus (USB) flash disk, or a removable hard disk. Thesoftware product includes a number of instructions that enable acomputer device (personal computer, server, or network device) toexecute the methods provided in the example embodiments. The softwareproduct may additionally include a number of instructions that enable acomputer device to execute operations for configuring or programming adigital logic apparatus in accordance with example embodiments.

Example apparatuses and methods described herein, in accordance withexample embodiments, can be implemented by one or more controllers. Thecontrollers can comprise hardware, software, or a combination ofhardware and software, depending on the particular application,component or function. In some example embodiments, the one or morecontrollers can include analog or digital components, and can includeone or more processors, one or more non-transitory storage mediums suchas memory storing instructions executable by the one or more processors,one or more transceivers (or separate transmitters and receivers), oneor more signal processors (analog and/or digital), and/or one or moreanalog circuit components.

In the described methods or block diagrams, the boxes may representevents, steps, functions, processes, modules, messages, and/orstate-based operations, etc. Although some of the above examples havebeen described as occurring in a particular order, it will beappreciated by persons skilled in the art that some of the steps orprocesses may be performed in a different order provided that the resultof the changed order of any given step will not prevent or impair theoccurrence of subsequent steps. Furthermore, some of the messages orsteps described above may be removed or combined in other embodiments,and some of the messages or steps described above may be separated intoa number of sub-messages or sub-steps in other embodiments. Evenfurther, some or all of the steps may be repeated, as necessary.Elements described as methods or steps similarly apply to systems orsubcomponents, and vice-versa. Reference to such words as “sending” or“receiving” could be interchanged depending on the perspective of theparticular device.

The above discussed embodiments are considered to be illustrative andnot restrictive. Example embodiments described as methods wouldsimilarly apply to systems, and vice-versa.

Variations may be made to some example embodiments, which may includecombinations and sub-combinations of any of the above. The exampleembodiments presented above are merely examples and are in no way meantto limit the scope of this disclosure. Variations of the innovationsdescribed herein will be apparent to persons of ordinary skill in theart, such variations being within the intended scope of the presentdisclosure. In particular, features from one or more of theabove-described embodiments may be selected to create alternativeembodiments comprised of a sub-combination of features which may not beexplicitly described above. In addition, features from one or more ofthe above-described embodiments may be selected and combined to createalternative embodiments comprised of a combination of features which maynot be explicitly described above. Features suitable for suchcombinations and sub-combinations would be readily apparent to personsskilled in the art upon review of the present disclosure as a whole. Thesubject matter described herein intends to include all suitable changesin technology.

The specification and drawings are, accordingly, to be regarded simplyas an illustration, and are contemplated to cover any and allmodifications, variations, combinations or equivalents.

What is claimed is:
 1. A method performed by a processing device, themethod comprising: generating a control signal for a transmission, thecontrol signal including a first identifier indicating a wirelessnetwork version of the transmission; and outputting the control signalin a trigger frame, wherein the first identifier is an identifier fieldor identifier subfield of the trigger frame.
 2. The method of claim 1,wherein the control signal is a separate field from a signal (SIG) fieldparticular to signaling information of the indicated wireless networkversion.
 3. The method of claim 1, wherein the control signal includes asecond identifier indicating a frame type of the transmission.
 4. Themethod of claim 1, wherein the indicated wireless network version is anInstitute of Electrical and Electronics Engineers (IEEE) 802.11 versionor an amendment version of the IEEE 802.11 version.
 5. A device,comprising: a processing device configured to: generate a control signalfor a transmission, the control signal including a first identifierindicating a wireless network version of the transmission; and outputthe control signal in a trigger frame, wherein the first identifier isan identifier field or identifier subfield of the trigger frame.
 6. Thedevice of claim 5, wherein the control signal is a separate field from asignal (SIG) field particular to signaling information of the indicatedwireless network version.
 7. The device of claim 5, wherein the controlsignal includes a second identifier indicating a frame type of thetransmission.
 8. The device of claim 5, wherein the indicated wirelessnetwork version is an Institute of Electrical and Electronics Engineers(IEEE) 802.11 version or an amendment version of the IEEE 802.11version.
 9. A method performed by a processing device, the methodcomprising: receiving as input a trigger frame, wherein the triggerframe includes a control signal for a transmission, the control signalincluding a first identifier indicating a wireless network version ofthe transmission, wherein the first identifier is an identifier field oridentifier subfield of the trigger frame.
 10. The method of claim 9,wherein the control signal is a separate field from a signal (SIG) fieldparticular to signaling information of the indicated wireless networkversion.
 11. The method of claim 9, wherein the control signal includesa second identifier indicating a frame type of the transmission.
 12. Themethod of claim 9, wherein the indicated wireless network version is anInstitute of Electrical and Electronics Engineers (IEEE) 802.11 versionor an amendment version of the IEEE 802.11 version.
 13. The method ofclaim 9, wherein the transmission is an uplink transmission.
 14. Adevice, comprising: a processing device configured to: receive as inputa trigger frame, which includes a control signal for a transmission, thecontrol signal including a first identifier indicating a wirelessnetwork version of the transmission, wherein the first identifier is anidentifier field or identifier subfield of the trigger frame.
 15. Thedevice of claim 14, wherein the control signal is a separate field froma signal (SIG) field particular to signaling information of theindicated wireless network version.
 16. The device of claim 14, whereinthe control signal includes a second identifier indicating a frame typeof the transmission.
 17. The device of claim 14, wherein the indicatedwireless network version is an Institute of Electrical and ElectronicsEngineers (IEEE) 802.11 version or an amendment version of the IEEE802.11 version.
 18. The device of claim 14, wherein the transmission isan uplink transmission.